Thermodynamic Study of Adsorption of Amaranth Dye on to Steam Activated Pigmented Rice Husk Carbon

Abstract

In the present work, thermodynamic study of adsorption of Amaranth dye on to steam activated pigmented carbon prepared from rice
husk (B.N. ORYZA SATIVA) was investigated The adsorbent was investigated under variable system parameters, such as intra particle
diffusion and temperature. The results of the present study have indicated the value of ΔH were in the range of -1.302 to -4.710 kJmol -1. This suggests the adsorption of Amaranth dye on SAPRHC as an exothermic process. The (ΔS) values were in the range -9.994 to -25.140 Jmol-1K-1, which is attributed to the higher degree of ordering of the small number of the dye molecules on the solid phase compared to their ordering in the aqueous phase. The adsorbent–dye interactions are spontaneous in all the cases supported by decrease in Gibbs energy. The results obtained indicate a potential use of SAPRHC for removing dyes like Amaranth dye from water.